Walid bin Attash, who is accused with Khalid Sheikh Mohammed and four others, said: 'The prosecution does not what us to hear or understand anything.' Image: Reuters

One of the alleged plotters of the 9/11 attacks has accused prosecutors in a hearing at Guantánamo Bay of placing so many restrictions on defence lawyers that there is no point in attending his own trial.

Walid bin Attash's outburst came after the five accused, including the alleged mastermind of 9/11, Khalid Sheikh Mohammed, sat in silence for hours as defence lawyers filed motions protesting at government intrusion into attorney-client privilege.

The military judge, Colonel James Pohl, told each of the alleged terrorists they had the right to choose not to attend this week's preliminary hearing, or to only attend parts of it. When Pohl asked each in turn if he understood, Bin Attash seized the moment to speak out.

"We have no motivation to come to court. We have been dealing with our attorneys for a year and a half, and we have not been able to build trust with them. Their hands are bound. The prosecution does not what us to hear or understand or say anything. They don't want our attorneys to do anything," he said.

Bin Attash's lawyer, Cheryl Bormann, who dresses in a black abaya out of respect to the religious sensibilities of her client, complained that she is obliged to turn over to the government copies of written confidential communications with him. Defence lawyers also raised issues about the handling of classified information, saying that it restricted their right to properly investigate issues.

The defence allegations of overly intrusive control were reinforced by an incident in which an invisible censor suddenly blacked out part of the proceedings to the public and press sealed off from the court and fed audio through a 40-second delay. The blackout came just as the defence began to discuss a motion to have Pohl issue an order preserving as evidence the secret overseas prisons where Mohammed, who appeared in court in a camouflage jacket with a beard dyed orange using berry juice, was waterboarded 183 times and the other accused allegedly tortured.

When the sound returned after about a minute, a defence lawyer protested that it had cut him off from reading material that is in the public record, including the title of his own motion.

The judge, clearly unsettled by the event, expressed surprised and said it was as "if some external body is turning the commission off". However, prosecutors did not appear to be surprised and said they would only discuss the matter in secret.

The accused men each face a range of charges, including 2,976 counts of murder. But the status of accusations of conspiracy remain unclear amid a dispute between the Obama administration and prosecutors at Guantánamo Bay following US appeals court rulings in other cases that conspiracy is not an offence under international law.

The chief prosecutor, Brigadier General Mark Martins, wants to drop the conspiracy charges because he believes the dispute about their legality will delay the trial further and provide grounds for appeal. But the Pentagon and justice department have told Martins they want the charges to remain pending a potential supreme court ruling on the issue.

Even without the conspiracy charge, the murder charges against Mohammed and his co-accused are enough to get them the death penalty. But relatives of some of those killed in the 9/11 attacks say they do not want to see the men executed.

Loreen Sellitto, whose 23-year-old son Matthew died in the World Trade Centre, said the accused men would suffer more in an American prison.

"I don't think there would be any better hell for them than to be under our rule. Death is too good," she told New York Daily News. "I would be very comfortable knowing that these men have to spend the rest of their lives locked up and controlled for the rest of their lives by the country they tried to destroy."

Phyllis Rodriguez, whose son Greg, 31, also died on 9/11, objected to executions on human rights grounds. "What kind of society are we if we condone state-sanctioned murder?" she said.

Rodriguez is supported by her husband, Orlando, who has previously testified in the case of attempted hijacker, Zacarias Moussaoui, to ask that he be spared the death penalty.

Later this week, the court is expected to hear motions seeking to require former President George W Bush to testify in the case, and to require the US government to produce official documents that authorised the CIA to abduct alleged terrorists and move them across international borders to the "black sites" for interrogation, a process known as rendition.

Defence lawyers are arguing that the CIA's mistreatment of the accused men was illegal "outrageous government misconduct" that should lead to the dismissal of the charges against the men.

"By its nature, torture affects the admissibility of evidence, the credibility of witnesses, the appropriateness of punishment and the legitimacy of the prosecution itself," the defence said in a written submission to the court.

Martins has said the government will not use evidence obtained from torture or similar treatment in its case.

For all the shortcomings of the Guantánamo trials, there was further evidence that the Obama administration has abandoned any attempt to fulfil the president's 2008 campaign promise to shut them down.

The New York Times reported that the State Department on Monday reassigned Daniel Fried, the special envoy for closing the Guantánamo prison, and will not replace him. Congress blocked Obama from moving the prisoners held in Cuba to the US for trial.